NEW YORK (Reuters) - North American cable and wire producers are buying more aluminum rod abroad at higher premiums due to production problems at Rio Tinto Alcan's Alma smelter in Quebec and Alcoa Inc's (>> Alcoa Inc.) Massena West smelter in upstate New York, market participants told Reuters.

Alma's rod customers have been scrambling to import raw material, some for the first time and from as far as Southeast Asia. Domestic rod producers have little spare capacity to fill the gap left by the 438,000-tonnes-per-year smelter, which slashed output by two-thirds more than three months ago.

Rio Tinto (>> Rio Tinto Limited) (>> Rio Tinto plc) cut production and declared force majeure in early January after locking out unionized workers due to a dispute over demands to limit the use of subcontract workers and guarantees of a certain number of union jobs at the plant.

There is no end in sight to the stand-off, with no new talks scheduled with the union, a spokesman said this week.

"Right now I am buying about 60 percent of my requirements for the United States outside of North America," said a source at a large, international cable maker who usually buys rod for his U.S. and Canadian operations from Alma but has gone abroad for the first time.

Importing is more complicated for inexperienced buyers, and costlier with freight and customs duties, said a smaller U.S.-based cable maker and Alma customer who has shipped metal into North America.

The first cable maker said he is paying twice as much to ship material from Asia-Pacific, Northern Europe, South America and the Middle East compared with his 2012 contract levels.

"Any pounds that I can find, I am buying," he said.

Cable makers would not say how much they were paying, but rod premiums are calculated using the Midwest ingot premium as a base.

That is already close to record highs at around 9-9.5 cents per lb, up from 8 cents at the start of the year due to overall supply tightness, with some traders saying they would not sell for less than 10 cents.

Rod, bar and profile imports into the United States rose more than 25 percent to over 11,400 metric tons (12,566 tons) in February from a year earlier, data from the U.S. International Trade Commission shows.

The race to replace Alma means desperate consumers are buying quality below their specifications. Alma produced high-purity rod, typically used in electrical transmission lines.

"It's to the point where if material is coming in that doesn't exactly meet your specs, you make it work," a physical dealer said.

Alcan's North American rival, Alcoa, has sold some spare output to Alma's customers, Timothy Reyes, president of Alcoa Materials Management, told Reuters.

But few producers have spare output as they sell on long-term contracts, another producer said.

Opportunities for domestic suppliers to fill the Alma gap have been limited further by the shutdown of Alcoa's Massena West casthouse following a fire at the end of March.

The U.S. producer continues to assess the damage, but there is no timetable for a restart, Chris Ayers, president of Alcoa's global primary aluminum business, told Reuters.

Massena West is smaller than Alma, with overall annual capacity of 130,000 metric tons, but traders said it has exacerbated the tightness. Massena West's annual rod capacity is 25,000 metric tons versus Alma's rod capacity of 100,000 metric tons.

(Additional reporting by Carole Vaporean; Editing by Josephine Mason and Dale Hudson)

By Chris Kelly

Stocks treated in this article : Alcoa Inc., Rio Tinto Limited, Rio Tinto plc